<!doctype html>
<meta charset="utf-8">
<title>CSS Selectors Invalidation: :nth-last-child(... of class) within shadow root</title>
<link rel="author" title="Zach Hoffman" href="mailto:zach@zrhoffman.net">
<link rel="author" title="Steinar H. Gunderson" href="mailto:sesse@chromium.org">
<link rel="match" href="nth-last-child-of-in-shadow-root-ref.html">
<link rel="help" href="https://drafts.csswg.org/selectors-4/#child-index">
<div id="host">
  <template shadowrootmode="open">
    <style>
      div:nth-last-child(even of .foo) {
        color: green;
      }
    </style>
    <div class="foo">Should be green</div>
    <div class="foo">No green</div>
    <div class="foo" id="toggler">No green</div>
  </template>
</div>
<script>
  host.offsetTop;
  host.shadowRoot.getElementById("toggler").classList.toggle("foo");
</script>
